21661022331415 has 32 divisors (see below), whose sum is σ = 26511797975040. Its totient is φ = 16983808642944.

The previous prime is 21661022331413. The next prime is 21661022331419. The reversal of 21661022331415 is 51413322016612.

It is a cyclic number.

It is not a de Polignac number, because 21661022331415 - 2¹ = 21661022331413 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21661022331413) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1049508666 + ... + 1049529304.

It is an arithmetic number, because the mean of its divisors is an integer number (828493686720).

Almost surely, 2^{21661022331415} is an apocalyptic number.

21661022331415 is a deficient number, since it is larger than the sum of its proper divisors (4850775643625).

21661022331415 is a wasteful number, since it uses less digits than its factorization.

21661022331415 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24711.

The product of its (nonzero) digits is 51840, while the sum is 37.

The spelling of 21661022331415 in words is "twenty-one trillion, six hundred sixty-one billion, twenty-two million, three hundred thirty-one thousand, four hundred fifteen".